Degenerative diseases of the eye are widespread among middle aged and elderly people. The most common of these diseases is glaucoma. A variety of topically applied medicinal compounds have been used to treat this disorder, although none is completely satisfactory. A class of compounds containing a benzodioxanyl moiety attached through an alkyl chain to an imidazole ring have now been found to be useful in the treatment of this disorder by the lowering of intraocular pressure. Compounds having the structures which disclosed as useful in lowering intraocular pressure herein previously have been described as .alpha..sub.2 blocking agents in U.S. Pat. Nos. 4,301,171, 4,302,468 and 4,315,021.